#top{
    width: 780px;
    height: 180px;
    margin-bottom: 4px;
    border: white solid 1px;
}
#banner{
    width: 780px;
    height: 150px;
    background: url(../img/banner.jpg);
}
#shang li{
    float: left;
    text-align: center;
    width: 78px;
    line-height: 33px;
}
#shang a{
    color: #256498;
    width: 78px;
    background: url(../img/button1.jpg);
    height: 33px;
    display: block;
}
#shang a:hover{
    background: url(../img/button1_bg.jpg);
    position: relative;
    bottom: 2px;
    right: 2px;
}